Triple warp ladder web



Dec. 20-, 1938. a. F, FRENCH TRIPLE WARP LADDER WEB Filed Aprii 22,1938' INVENTOR. GEORGE E FRENCH ATTORNE Patented Dec. 20, 1938 TRIPLEWARP LADDER WEB George Frederick French, Manchester, England, assignorto Thomas French & Sons Limited, Manchester, England, a corporation ofGreat Britain Application April 22, 1938, Serial No. 203,583 n GreatBritain December 22, 193':

17 Claims. (Cl. 139-384) This invention relates to ladder web, as, for

example,-such as is used for supporting the laths of Venetian blinds orfor holding pieces of cork or the like in sun helmets. Ladder web of thecharacter dealt with herein has long been known and used, especially forVenetian blinds. ladder webconsists essentially of two outer bands withnarrower cross-straps between said outer bands at regular spacedintervals. The said cross-straps are alternately near one or the otheredge of said outer bands.

Originally, it was customary to weave each of said outer bands and thecross-straps separately Such and then cut the same to suitable lengthsand,

sew the parts together, by hand. Later,'a loom was developed for weavingboth the outer bands and the cross-straps simultaneously and securingthe parts together in their final positions. This method of manufactureoriginated many years ago and is described in British Patent No. 229 of1869. This method of manufacture has been in universal use ever sincethe date of said patent and has continued in use without any substantialmodification up to the present invention.

In the said previously known make of webbing, the connections of thecross-straps with the outer bands were relatively short, about half tothree quarters of an inch for the largest size of webbing, due to theuse of a single set of warps for each row of cross-straps, and due alsoto the spacing of the cross-straps requiring-to be such as to allow ofthe blind laths overlapping, to shut out the light, when in use. Again,the connections of the cross-straps warps with the outer on the outerband warps, and binding them thereto by a few of the weft threads of thebands. With such short connections, and owing also to the strap warpsbeing composed of fine thread, it

has been a common fault for the strap warps to pull out, or break awayfrom the outer bands, in

use. I

The employment of fine warps threads was mainly to prevent bulging ordistortion of the edges of the outer bands adjacent the points where thecross-straps were connected, and for a like reason the cross-straps wereconnected at a material distance from the edges of the bands. Thecross-straps were bound to the bands along rathernarrow areas and thebindings-in were visible from the outside, especially in the case of atwill weave of band.

- The present invention is intended and adapted to. overcome thedisadvantages of the prior method of manufacturing ladder web and toprobands were effected by superimposing the same,

1 which were used for the outer bands andthe gether but at the same timewill afford the necesvide a construction in which the cross-straps aremore firmly united with the outer bands, in which there is no bulging ofthe edges of said bands even when the cross-straps are located up to thevery edge of said bands. 5 It is a further object of the presentinvention to provide a construction in which there is no blemish of thetwill weave where used, in which thecross-straps may be short and lieclose tosary firmness of connection with the outer bands, in which thecross-straps need not be staggered but may be in a single row,superimposed one above the other.

It is a still further object of the present invention to provide amethod of weaving ladder web in which the cost of productionis greatlyreduced, in which coarser threads may be utilized in the weaving, fromwhich narrow web will result, and which is adaptable for use inproducing weftless ladder web of great strength and utility.

In accordance with the present invention, I do not provide four sets ofwarp threads, two sets of other two sets of which were used for thecrossstraps, as was customary in the prior art. On the other hand, Iprovide essentially only three sets of warp threads, each of which insuccession forms a length of an outerband, them a cross-strap, and thena corresponding length of the opposite outer band. Then saidwarp threadscross over into the first mentioned outer band and weaving is continuedin the same cycle, namely, said threads forming alength of the saidfirst named outer band,then. the cross-strap, and then the length ofsaid opposite outer band, and so on. The two cross-straps described arenot adjacent to each other but there areinterposed therebetween twoother cross-straps formed from the other two sets of warp threads hereindescribed.

The second set of warp threads, for purposes of illustration, begins ator about. that area of the first named outer band at which the firstmentioned warp threads leave the same to form a cross-strap. Said secondset follows along after the first named set, forming successively alength of outer band, across-strap, a: length of the opposite outerband,-and a cross-overto the first mentioned band. The third set of warpthreadsv follows the first two named sets in exactly the same order,starting, for example,-at the area where the second set of warp threadsbegins to form a cross-strap and forming successively a 66 threadsoutlined above, the outer bands are woven in their entirety. Inaddition, one or more weft threads may be'provided for weaving thecross-straps. However, in a preferred form, the cross-straps areweftless and therefore no .additional weft threads are necessary withoutany sacrifice of strength or utility.

However, in actual practice, it is not possible to make perfect ladderweb with only three sets of warp threads. Since, in the usual ladder webthe adjacent cross-straps are in staggered relation in two rows, thereis usually provided three sets of warp threads for each row ofcross-straps. In addition, there is ordinarily provided ground or basewarp threads for each of the outer bands which do not cross over but arewoven contin uously into their respective bands.

In the accompanying drawing, constituting a part hereof and in whichlike-reference characters indicate like parts, Fig. 1 is a diagrammaticview looking from the side of a length of ladder web made in accordancewith the prior art. The outer bands of the ladder web are shown agreater distance apart than is customary in order I to clarify theconstruction;

Fig. 2 is a similar diagrammatic view of a length of ladder web made inaccordance with the present invention. There is no showing of the secondset of cross-straps illustrated in Fig. 1 in order to clarify theshowing and each of the three sets of warp threads are illustrateddifferently in order that the course thereof maybe clearly followed; and

Fig. 3 is a diagrammatic plan view of a piece of ladder web made inaccordance with the present invention.

In the prior art as illustrated in Fig. 1, it was customary in theweaving to produce two outer bands I and 2, respectively, arranged inparallel relation. One of the sets of cross-straps con sisted of abinding-in 3 formed by attachinginthe loom of a section of thecross-strap into outer band 2, said binding-in being superimposed uponthe outer band and increasing the thickness at said point. From thebinding-in, a cross-strap 4 passed over to outer band I and a similarbinding-in 5 was formed on the inner surface thereof. This binding-in ofcourse increased the thickness of the band at said point. Thereafter,there was a cross-over 6 onto outer band 2, then a similar binding-in I,a similar cross-strapii, and a similar binding-in 9, and so on,repeating the cycle. The above described set of cross-straps was, say,located near the front edges of the outer bands and a second set ofcross-straps was formed near the opposite sides of said outer bands. InFig. 1 this is illustrated by the binding-in III on outer band 2, thecross-strap II, the binding-in l2 on the opposite outer band I, thecross-over l3, and the binding-in ll on outer band 2, the cross-strapl5, and so on, repeatingthe cycle.

In Fig. 2 I have illustrated diagrammatically the radically differentmethod of making ladder web in accordance with the present invention. Inorder to form the lower outer band, a weft thread I6 is provided whichcontinuously formssaid outer band cooperating with a series of warpthreads II. The weaving of threads l6 and I1 forms a predeterminedsection of the lower outer band. Thereafter, the warp threads leave saidouter band, forming a cross-strap I8, and then entering into the upperouter band at l9, being woven into the same by weft thread 20. After apredetermined length thereof has been woven into said upper outer band,the warpthreads cross over, as shuwn at=2l, and weaving is continuedwith weft thread IE to form a predetermined section 22 of the lowerouter band. The cycle then is repeated.

A second set of warp threads 23, shown crossing over from the upper tothe lower outer band, enters the lower band at approximately thetransverse line where threads l8 leave the same to form a cross-strap.Threads 23-are interwoven with weft thread IE to provide a predeterminedlength 24 of the lower'outer band. Thereafter the warp threads, inpassing to the upper outer band, form the cross-strap 25 and they arewoven' into the upper band by means of weft thread 20 to form a length26 of the upper outer band. Then said warp threads cross over, as shownat 21, again entering the lower outer band and being woven into the sameby weft thread It. The cycle is, of course, repeated.

The third set of warp threads 28 is woven into the upper outer band forthe length 28 beginning at the transverse line approximately where warpthreads 23 left the. same to cross over. when the weaving-in of warpthreads 28 reaches the point where warp threads l8 enter the uppero'uter band, .said threads 28 cross over, as shown at 29, to the lowerouter band at approximately the point where warp threads 25 leave thesame to form a cross-strap. They are woven into the a lower band withweft thread ii for a predetermined length 30. They leave said lowerouter.

band at approximately the area where the crossover warp threads 2| entersaid lower outer band and form the cross-strap 3| entering the upperouter band at approximately the area where cross-over threads 21 leavethe same. They are then woven into the upper outer band for apredetermined length 32, the cycle is, of course reever, a second setalternating with the described set may be made as is common practice.This is accomplished by dividing the sets of warp threads into two partswhereby only part thereof go through the cycle shown in Fig. 2 and theother part may alternate therewith along the opposite edges of the outerbands. Furthermore, if desired, a central space may be left between thetwo setsof cross-straps. In Fig. 3 I have illustrated a form of ladderweb made in accordance with the present invention. Section A is thatformed, for example, by the weaving-in of warp threads II. Section B isformed by the weaving-in of warp threads 24, and Section C is formed bythe weaving-in of warp threads ll. Thereafter, the cycle repeats itself.At X is shown the area at which the warp threads cross over to form' thecross straps.- It will be noted that this forms only one side of theladder web. The other side thereof maybe similarly formed with SectionsA, B and C of outer bands with cross-straps X alternating withcross-straps X.

come to approximately the outer edges of the outer bands. Ihe'sectiomA,3,0 andthelike may be of plain weave or twill weave, and-when they areof plain weave it is desirable to have the section Y of twill weave forappearance sake. It will be noted that each of the sets of warp threadsforms one outerband, a cross-strap, and the op-.

posite outer band, and the cycle continues indefinitely. This isaconstruction which is entirely different from that used heretofore andwhich has many advantages thereover. Because of the long weaving-in areainto the outer bands, the cross-strap ismuch stronger because saidweaving-in is several times that previously used. This makes certainthat the cross-straps cannot pull out under severe use and makes morepractical a weftless cross-strap. Since the weave of the outer bands isuniform, there do not appear any unsightly binding-in areas. It ispossible by the use of the present invention greatly to increase theproduction of a loom for various reasons, as, 'for example, becausecoarser weft threads may be used, less picks are required, doublethreads may be. utilized'in the shuttle,-and only three. sets of warpthreads are necessary in place of four.

There may be obtained any desired lap-over of the laths because thespacing of the cross-straps can be very easily changed. It also becomespractical to make narrower outer bands with the cross-straps close tothe edge and even without any staggering thereof.. In place of at leastsome of the warp threads, I may use braid, cord, or tape which arebound-in to form the cross-straps and at least part of the outer bands.It is feasible to use plain weave instead of a twill, particularly forthe narrower outer bands in order to give a stronger binding-in, sincethere are several times as many crossings of the warp and weft threadsin the plain weave. .placed much closer together than heretofore, sincea firm connection thereof into the outer bands is obtained, somethingwhich was impossible by the prior art method. The cost of pro- 'ductionvis, of course, greatly reduced. It is, of

course, understood that the cross-over from 'one' ing-in the strap warpsthe coarser yarns can be used without causing any bulging of thebandin'gs where the strap connections are made. Alternatively, ordinaryfine 'warp may be used, and

. reliance placed solely on the new method of uniting the straps withthe bandings to obtain the said advantages. Owing to the improved modeof uniting the cross-strap warps with the bandings,

the cross-straps may lie nearer the edges of the bandings withoutcausing bulging of such edges, and by weaving them as part of thebandings, the joinings will not show through and the bandings maybe ofthe usual twill weave, with consequent advantage in appearance. theincreased strength of the bindings-in, the

-webbing and cross-straps may be made narrower than heretofore, andthecross-straps may also lie at shorter distances apart to suit narrowlaths. The cross-straps may all lie in one row, and to allow them to lieat short distances apart, the free warps may extend through the nextcrossstrap and afterwards he cut away. When arranged in two rows, therows will usually be The cross-straps may be.

And, owing to spaced apart to allow the usual blind cord to passbetween, and when all arranged in one row, the said cord will beconnected to the blind laths at a point beyond the webbing.

Although I have described my invention set- .ting forth a singleembodiment thereof and have indicated a few variations therein, it willbecome apparent that there are many ways of carrying out the principalidea involved. The idea resides in the use of a minimum of three sets ofwarpv threads which form successively an outer band, a cross-strap andthe opposite outer band, but it is, of course, understood thatadditional sets of warp threads may be utilized within the scope of theinvention. Also, some warp threads may be provided which do not crossover at all but which continue to form but one of the outer bands. Theseand other changes in the details of my invention may be made within thespirit thereof, and the scope of my invention is .not to be limitedexcept by the claims appended hereto.

What I claim is:

1. In ladder web including two outer bands and having cross-straps woventherein andspaced a given distance apart, the improvement whichcomprisesa plurality .of sets of warp threads woven with weft thread ineach of the outer bands, each set forming successively a section of anouter band equal in length to said given distance, a cross-strap, asection of the opposite outer band equal in length to said givendistance, a crossover, a section of said first outer band equal inlength to said given distance.

2. In ladder web including two outer bands and having cross-straps woventhereinand spaced a given distance apart, the improvement whichcomprises a plurality of sets of warp threads woven with weft thread ineach of the outer bands, each set forming successively a section of anouter band equal in length to said given distance, a cross-strap, asection of the opposite outer band equal in length to said givendistance, a cross-over, a section of said first outer. band equal inlength to said given distance, and a cross-strap, the latter having atleast one othercross-strap interposed therebetween.

3. In ladder web including two outer bands" and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises a plurality of sets of warp threads woven with weft thread ineach of the outer bands, each set forming successively a sec tion of anouter band equal in length to said iven distance, a cross-strap, asection of the opposite 'outer band equal in length to said givendistance, a cross-over, a section ofsaid first outer :band equal inlength to said given distance, each set of warp threads then crossingover and repeating the aforesaid arrangement. 4. In ladder web includingtwo outer bands and having cross-straps woven therein and spaced a givendistance apart, the improvement which comprises three sets of warpthreads woven with weft thread in each of the outer bands, each setforming successively a section of an outer band weft thread in each ofthe outer bands, each set 7 !orming successively a section of: an outerband- ,10 and having cross-straps woven therein and spaced a givendistance apart, the improvement which comprises a plurality of sets ofwarp threads woven with weft thread in each of the outer bands, each setforming successively a section of one side of an outer band equal inlength to said given distance, a cross-strap, a section of the cor-'responding side of the opposite outer band equal in length to said givendistance, a cross-over, a section of said first outer band equal inlength to said given distance,

7. In a ladder web including two outer bands and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises a plurality of sets of warp threads woven with weft thread ineach of the outer bands, each set forming successively a section of oneside of an outer band equal in length to said given distance, across-strap, a section of the 'corresponding side of the opposite outerband equal 80 in length to said given distance, a cross-over, a sectionof said first outer band equal in length to said given distance, asecond similar plurality of sets of warp threads woven with weft threadin each of the outer bands and forming successively a section of theouter side of said first outer band, a cross-strap, a section of thecorresponding side of the opposite outer band, and a crossover.

8. In ladder web including two outer bands 40 and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises three sets of warp threads woven with weft thread in each ofthe outer bands, each set forming successively one side of a section ofan outer band equal in length to said given distance, a cross-strap, asection of the corresponding side of the opposite outer band equal inlength to said given distance, a cross-over, a section of said firstouter band equal in length so to said given distance.

9. In ladder web-including two outer bandsand having cross-straps woventherein and spaced a given distance apart, the improvement whichcomprises three sets of warp threads woven with iweft thread in each ofthe outer bands, each set forming successively one side of a section ofan outer band equal in length to said given distance,

a cross-strap, a section of the corresponding side of the opposite outerband equal in length to said given distance, a cross-over, a section ofsaid first outer band equal in length to said given distance, a secondsimilar plurality of sets of warp threads woven with weft thread in eachof the outer bands and forming successively 'a section 68 of the othersideof said firstouter band, a crossstrap, a section of thecorresponding side of the opposite outer band, and a cross-over.

' '10. In ladder web including two outer bands and having cross-strapswoven therein and 70 spaced a given distance apart, the improvementwhich comprises a plurality of sets of warp threads woven-with weftthread in each of the outer bands, each set forming successively asection of one side of an outer band equal in length to said givendistance, a cross-strap, a section of straps extending to substantiallythe edges of said the corresponding side of the opposite outer bandequal in length to said given distance, a crossover, a section of saidfirst outer band equal in length to said given distance, a secondsimilar plurality of sets of warp threads woven with'wett 5 thread ineach of the outer bands and forming successively a section of theotherside of said first outer band, a cross-strap, a section of thecorresponding side of the opposite outer band, a cross-over, and anadditional set of warp threads l0 constituting a central portion of eachouter band, the latter warp threads remaining continuously in theirrespective bands.

11. In ladder web including two outer bands and having cross-strapswoven therein and. 15

spaced a given distance apart, the improvement which comprises threesets of warp threads woven with weft thread in each of the outer bands,each set forming successively one side of a section of an outer bandequal in length to said given D distance, a cross-strap, a section of:the corresponding side of the opposite outer band equal in length tosaid given distance, a cross-over, a section of said first outer bandequal in length to said given distance, a second similar plurality 25 ofsets of warp threads woven with weft threads in each of the outer bandsand forming successively a section of the other side of said firstouter. band, a cross-strap, a section of the corresponding side of theopposite outer band, a cross-over, and an additional set of warp threadsconstituting a central portion of each outer band, the latter warpthreads remaining continuously in their respective bands. 12; In ladderweb including two outer bands and having cross-straps woven therein andspaced a given distance apart, the improvement which comprises aplurality of sets of warp threads woven with weft thread in each of theouter bands, each set forming successively a section of 4( an outer bandequal in length to said given distance, a cross-strap; a section of theopposite outer band equal in length to said given distance,

a cross-over, a section of said first outer band equal in length to saidgiven distance, said cross- 4| str ps being weftless.

13. In ladder web including two outer bands and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises three sets of warp threads woven with g weft thread in each ofthe outer bands, each set forming successively a section of an outerband equal in length to said given distance, a crossstrap, a section ofthe opposite outer band equal in length to said given distance, across-over, a I section of said first outer band equal in length tosaid" given distance, said cross-straps being weitless.

14.- In ladder web including two outer bands and having cross-strapswoven therein and I spaced a given distance apart,-the improvement whichcomprises a plurality of sets of warp threads woven with weft thread ineachof the Y outer bands, each set forming successively a section of anouter band equal in length to said given distance, a cross-strap, asection of the opposite outer band equal in length to said givendistance, a cross-over, a section of said first outer band equal inlength to said given distance, said crossouter bands.

15. In ladder web including two outer bands and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises three sets of warp threads woven 1 aiupas,

with weft thread in each of the outer bands, each set formingsuccessively a section of an outer band equal in length to said givendistance, a cross-strap, a section of the opposite outer band equal inlength to said given distance, a crossover, a section of said firstouterband equal in length to said given distance, said cross-strapsextending to substantially the edges of said outer bands. 7,

16. In ladder web including two outer bands and having cross-strapswoven therein and spaced a given distance apart, the improvement whichcomprises a plurality of sets of: warp threads woven with weft thread ineach of the outer bands, each set forming successively'a section of oneside of an outer band equal in length to said given distance, across-strap, a section of the corresponding side of the opposite outerband equal in length to said given distance, a crossover, a section ofsaid first outer band equal in length to said given distance, a secondsimilar plurality of sets of warp threads woven withweft thread in eachof the outer bands and forming successively a section of the other-side01' said first outer band, a cross-strap, a section of the correspondingside of the opposite outer band, and a cross-over, said cross-strapsextending respectively to an edge of said outer bands.

17. In ladderweb including two outer bands and having cross-straps woventhereinand, spaced a given distance apart, the improvement set formingsuccessively one side of a section of an outer band equal in length tosaid given distance, a cross-strap, a section of the corresponding sideof the opposite outer band equal in length to said given distance, across-over, a section of said first outer band equal in length to saidgiven distance, a second similar plurality of sets of warp threads wovenwith weft thread in each of the outer bands and-forming successively asection of the other side of said first outer band, a cross strap, asection of the corresponding side of the opposite outer band, and across-over, said crossstraps extending respectively to an edge of said iouter bands.

GEORGE FREDERICK FRENCH.

which comprises three sets of warp threads woven with weft thread ineach of the outer bands, each

